Due to their high power density and higher efficiency compared to analogue longitudinally regulated solutions, DC-DC converters are now widely used. In highly simplified terms, such a system can be described by the fact that a high-frequency alternating voltage is generated using a semiconductor switching element and this voltage is converted back into a DC voltage using a higher-order filter. This output voltage is detected and regulated to a target value by means of a control system.
An example of a DC-DC converter is a boost converter. Using this it is possible to convert a DC input voltage into a higher output voltage. The ratio of input to output voltage is essentially defined by the duty cycle of the PWM signal (pulse width modulation) at the switching element, for example a transistor.
A DC-DC converter in the form of a step-up converter is known from DE 103 48 265 A1. The step-up converter comprises a regulating device for stepping-up an input voltage to a desired target voltage level for an output voltage. During the step-up process the regulating device performs a target/actual value comparison between the desired target voltage level for the output voltage and its current actual value.